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Abstract:

Disclosed are a method and an apparatus for generating signal patterns
used for a transmission/reception process between a terminal and a base
station by using a modular sonar sequence.

Claims:

1-41. (canceled)

42. A method of generating a positioning reference signal pattern in an
OFDM-based wireless communication system including one or more base
stations and one or more UEs, each of the base station and UEs including
one or more antennas and transmitting and receiving a particular signal
including one or more symbols in resource blocks, each of the resource
blocks including a plurality of OFDM subcarriers and a plurality of OFDM
symbols in one time slot within a radio frame, the radio frame including
a plurality of subframes, each of the subframes including two slots, the
method comprising: forming a basic positioning reference signal pattern
in a 1/2 resource block including six OFDM subcarriers and two slots
configuring one subframe by a particular sequence; forming a positioning
reference signal pattern by repeating the basic positioning reference
signal pattern formed in the 1/2 resource block 2NRBDL times
along a frequency axis, wherein NRBDL is the number of all
resource blocks corresponding to a downlink system bandwidth; and forming
a positioning reference signal pattern differently along a time axis by
differently allocating the basic positioning reference signal pattern
formed in the 1/2 resource block to Nsubframe number of subframes
for positioning at each particular period according to cell-specific
information and subframe number for positioning while giving different
vshift values, each of which corresponds to an equal-sized cyclic
shift value along the frequency axis for the OFDM subcarrier position at
which a positioning reference signal is formed in a symbol for the
positioning reference signal.

43. The method of claim 42, wherein the formed positioning reference
signal pattern corresponds to a position of ak,l.sup.(p), which is a
symbol modulated into a complex value used as a symbol for a positioning
reference signal for an antenna port p, in a resource grid corresponding
to a two dimensional domain of frequency (subcarrier) and time (symbol),
at the nsth slot of a subframe for each positioning, and the
method further comprises mapping a positioning reference signal sequence
rl,n.sup.(m) to ak,l.sup.(p).

45. The method of claim 42, wherein forming of the basic positioning
reference signal pattern in the 1/2 resource block comprises: forming a
primary basic positioning reference signal pattern at a position of a
subcarrier corresponding to an ith value of a sequence in a
frequency domain, with respect to each ith symbol from a final symbol in
each of the two slots and the particular sequence having a length of N,
wherein 1.ltoreq.i≦N; and forming the basic positioning reference
signal pattern by puncturing positioning reference signals at positions
corresponding to resource elements, in which a Primary Synchronization
Signal (PSS), a Secondary Synchronization Signal (SSS), and a Broadcast
Channel (BCH) exist, a symbol axis, in which a Cell-specific Reference
Signal (CRS) exists, and control areas including a Physical Downlink
Control Channel (PDCCH), a Physical Hybrid-ARQ Indicator Channel (PHICH),
and a Physical Control Format Indicator Channel (PCFICH) in the generated
primary basic positioning reference signal pattern.

46. The method of claim 45, wherein the particular sequence having a
length of N is {0, 1, 2, 3, 4, 5, 6} and N has a value 6.

47. The method of claim 42, wherein, in forming of the basic positioning
reference signal pattern in the 1/2 resource block, for v indicating a
value for defining locations of different positioning reference signals
in a frequency domain, NsymbDL indicating the number of all
OFDM symbols in each slot in a downlink, and an Ith OFDM symbol for
a positioning reference signal at each nsth slot, the position
in a resource grid corresponding to a two dimensional domain of frequency
(subcarrier) and time (symbol), at which the basic positioning reference
signal pattern is formed, is determined by using equations, v = 5 - l
+ N CP ##EQU00007## l = N symb DL - i for i =
1 , 2 , 4 , , 4 + ( n 5 mod 2 ) + N CP
##EQU00007.2## N CP = { 1 for normal CP 0
for extended CP . ##EQU00007.3##

49. The method of claim 42, wherein, in forming of the positioning
reference signal pattern, for NBEDL indicating the number of
all resource blocks corresponding to a downlink system bandwidth,
NscRB indicating the number of subcarriers in a single resource
block, and a kth subcarrier in an entire system bandwidth including
NRBDLNscRE number of subcarriers, the position of an
ith OFDM symbol, which corresponds to a symbol for a positioning
reference signal at an nsth slot, and a kth subcarrier in
a resource grid corresponding to a two dimensional domain of frequency
(subcarrier) and time (symbol), at which the positioning reference signal
pattern is formed, is determined by using equations,
k=6m+(v+vshift) mod 6 m=0, 1, . . . , 2NRBDL-1

50. The method of claim 49, wherein vshift corresponds to a
remainder remaining after dividing a value, which is generated by a
function of a subframe number and cell-specific information, by 6, which
corresponds to a maximum available frequency shift value, and vshift
is obtained by deriving one or more pseudo-random sequence values from a
pseudo-random sequence, which is generated with cell-specific information
as an initial value, by a function of positioning subframe numbers,
multiplying the derived pseudo-random sequence values by a predetermined
constant, calculating a sum of the multiplied values, and then obtaining
a remainder remaining after dividing the sum by 6, which corresponds to a
maximum available frequency shift value.

52. The method of claim 42, wherein the particular period corresponds to
a period of 16, 32, 64, or 128 frames.

53. The method of claim 42, wherein the Nsubframe number corresponds
to one, two, four, or six, and the Nsubframe number of subframes are
sequentially located at an initial part of a particular frame including
the subframes to which the positioning reference signals have been
allocated.

54. The method of claim 53, wherein the subframes to which the
positioning reference signals have been allocated are subframes
corresponding to 0.1%˜1% of all frames of the particular period.

[0003] Embodiments of the present invention relate to a method and an
apparatus for generating a signal pattern used in a
transmission/reception process between a terminal and a base station in a
wireless communication system. More particularly, embodiments of the
present invention relate to a method and an apparatus for generating a
cell-specific Positioning Reference Signal (PRS) pattern, which is a
signal pattern used to measure a location of a UE (User Equipment)
through a reference signal (or a pilot) in an OTDOA (Observed Time
Difference Of Arrival) manner in an OFDM (Orthogonal Frequency Division
Multiplexing) based wireless mobile communication system, among signal
patterns.

[0004] 2. Discussion of the Background

[0005] A terminal or a base station transmits and receives a predetermined
signal in a specific time and frequency band for a channel estimation, a
position estimation, and a transmission/reception of information for
control information or a scheduling required for a process of wireless
communication between the terminal and the base station. That is, the
terminal or the base station may insert a specific signal or symbol into
a 2-dimensional domain grid of a time/frequency at regular intervals or
irregular intervals. A form in which the specific signal is inserted into
a 2-dimensional region of a time/frequency corresponds to a signal
pattern. For example, a Reference Signal (RS) is transmitted in a
specific time and frequency band for a frequency domain channel
estimation, and a rule for the specific time and frequency band in which
the reference signal is transmitted corresponds to a reference signal
pattern.

[0006] The present invention relates to a technology of forming the signal
patterns by using a modular sonar sequence. More particular, the present
invention relates to a technology of forming a cell-specific positioning
reference signal pattern, which is a signal pattern used to measure a
position of a UE through a reference signal in an OTDOA manner in an OFDM
based wireless communication system.

SUMMARY

[0007] Additional features of the invention will be set forth in the
description which follows, and in part will be apparent from the
description, or may be learned by practice of the invention.

[0008] Exemplary embodiments of the present invention disclose a method of
generating a signal pattern in a wireless communication system including
one or more base stations and one or more User Equipments (UEs), each of
the base station and UEs including one or more antennas and transmitting
and receiving a particular signal including one or more symbols in
resource blocks, each of the resource blocks including a plurality of
Orthogonal Frequency Division Multiplexing (OFDM) subcarriers and a
plurality of OFDM symbols in one time slot within a radio frame, the
radio frame including a plurality of subframes, the method including
forming a pattern of the particular signal from the second M×N
modular sonar sequence and mapping the signal, and an apparatus and a
transmission/reception device thereof.

[0009] Further, a method of using a sequence having the same
characteristic as that of the M×N modular sonar sequence in
generating signal patterns, and an apparatus and a transmission/reception
device thereof.

[0010] It is to be understood that both the foregoing general description
and the following detailed description are exemplary and explanatory and
are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings, which are included to provide a further
understanding of the invention and are incorporated in and constitute a
part of this specification, illustrate embodiments of the invention, and
together with the description serve to explain the principles of the
invention.

[0012] FIG. 1 illustrates an apparatus for forming a Positioning Reference
Signal (PRS) pattern by using a M×N modular sonar sequence
according to an aspect of the present invention;

[0013] FIGS. 2 and 3 illustrate an embodiment in a structure of an MBSFN
(Multicast Broadcast Single Frequency Network) subframe of an LTE (Long
Term Evolution) system according to the aspect of the present invention;

[0014] FIG. 5 illustrates an embodiment in a structure of a normal
subframe having a normal CP (Cyclic Prefix) of an LTE system according to
the aspect of the present invention;

[0015]FIG. 6 illustrates an embodiment in a structure of a normal
subframe having an extended CP of an LTE system according to the aspect
of the present invention;

[0016] FIGS. 7 and 8 illustrate another embodiment in the structure of the
normal subframe having the extended CP of an LTE system according to the
aspect of the present invention;

[0017]FIG. 9 illustrates an apparatus for forming a PRS pattern by using
an M×(N-N') modular sonar sequence according to another aspect
(second aspect) of the present invention;

[0018] FIGS. 10 and 13 illustrate an embodiment in the structure of the
MBSFN subframe of an LTE system according to another aspect of the
present invention;

[0019] FIGS. 11 and 14 illustrate an embodiment in the structure of the
normal subframe having the normal CP of an LTE system according to
another aspect of the present invention;

[0020] FIGS. 12 and 15 illustrate an embodiment in the structure of the
normal subframe having the extended CP of an LTE system according to
another aspect of the present invention;

[0021] FIG. 16 illustrate structures of a frame, in which a positioning
reference signal pattern is formed in one or more subframes, and a
subframe according to another embodiment of the present invention;

[0022] FIG. 17 illustrates a signal generation structure of a downlink
physical channel in a wireless communication system to which embodiments
of the present invention are applied;

[0023] FIG. 18 illustrates a structure of a receiver in a wireless
communication system; and

[0024] FIGS. 19 and 20 illustrate an embodiment in a structure a normal
subframe having the normal CP and the extended CP of an LTE system
according to still another aspect of the present invention.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

[0025] The above and other objects, features and advantages of the present
invention will be more apparent from the following detailed description
taken in conjunction with the accompanying drawings, in which:

[0026] Exemplary embodiments now will be described more fully hereinafter
with reference to the accompanying drawings, in which exemplary
embodiments are shown. This disclosure may, however, be embodied in many
different forms and should not be construed as limited to the exemplary
embodiments set forth therein. Rather, these exemplary embodiments are
provided so that this disclosure will be thorough and complete, and will
fully convey the scope of this disclosure to those skilled in the art.
Various changes, modifications, and equivalents of the systems,
apparatuses, and/or methods described herein will likely suggest
themselves to those of ordinary skill in the art. Elements, features, and
structures are denoted by the same reference numerals throughout the
drawings and the detailed description, and the size and proportions of
some elements may be exaggerated in the drawings for clarity and
convenience.

[0027] An object of the present invention is to provide a new effective
method of forming patterns of signals transmitted and received by a
terminal or a base station in a specific time and frequency band for a
channel estimation, a position estimation, and a transmission/reception
of information for control information or a scheduling required for a
process of wireless communication between the terminal and the base
station.

[0028] Further, an object of the present invention is to provide a new
effective method of constructing a reference signal for the positioning
in a new resource allocation structure where a communication
infrastructure is changed from an existing asynchronous CDMA-based WCDMA
method to OFDM-based multiplexing method and access method in detecting a
UE (User Equipment) location through a reference signal (or a pilot) for
the positioning in an OTDOA (Observed Time Difference Of Arrival) manner
in the OFDM (Orthogonal Frequency Division Multiplexing)-based wireless
mobile communication system.

[0029] An object of the present invention is to provide excellent PRS
(Positioning Reference Signal) patterns in an aspect of the number of
distinct cell-specific patterns and the performance for a more accurate
positioning method required by the development of a communication system
such as an increase in a movement velocity of a UE, a change in an
interference environment between base stations, and an increase in
complexity, in the OFDM (Orthogonal Frequency Division
Multiplexing)-based wireless mobile communication system.

[0030] In order to achieve the above objects, the present invention
provides a method of generating signal patterns having different patterns
specific for each cell in a resource allocation structure by using the
modular sonar sequence. Accordingly, greatly more patterns according to
system-specific information may be generated in comparison with a
conventional method in an aspect of the number of distinct patterns, and
although each pattern is cyclic-delayed on a time (a symbol in an OFDM
structure) axis or a frequency (a subcarrier in an OFDM structure) axis,
errors generated by overlapping with an original pattern may be reduced
in comparison with a conventional method in an aspect of distinct
performances.

[0031] The present invention provides a method of generating signal
patterns having different patterns specific for each cell by using the
modular sonar sequence and allocating the generated signal patterns to
one or more subframes.

[0032] An effect of a method of generating a Positioning Reference Signal
(PRS) pattern by using the aforementioned modular sonar sequence, which
is one embodiment of the present invention, is described below.

[0033] According to the method of generating the PRS pattern by using the
modular sonar sequence, although each pattern is cyclic-delayed on a time
(a symbol in an OFDM structure) axis or a frequency (a subcarrier in an
OFDM structure) axis, errors generated by overlapping with an original
pattern may be reduced in comparison with a conventional method and
positioning reference signal patterns having greatly more different
patterns specific for each base station (cell) may be generated in a
resource allocation structure in comparison with the conventional method.

[0034] Positioning methods of providing various location services in a
WCDMA (Wideband Code Division Multiple Access) and location information
required for communication are largely based on three methods, which are
a cell coverage-based positioning method, an OTDOA-IPDL (Observed Time
Difference Of Arrival-Idle Period DownLink) method, and a
network-assisted GPS method. Each method is complementary to each other
rather than competitive, and properly used according to a different
objective.

[0035] Among the three methods, the OTDOA method is based on measuring
relative arrival times of reference signals (or pilots) from different
base stations (or cells) while moving. A UE (or MS (Mobile Station))
should receive corresponding reference signals (RS) from at least three
different base stations (or cells) for a location calculation. In order
to make an OTDOA location measurement easy and avoid a near-far problem,
the WCKMA standard includes an IPDL (Idle Periods in DownLink). Although
a RS (or a pilot) from a serving cell, in which a current UE is located,
on the same frequency is strong (or MS), the UE should be able to receive
an RS (or a pilot) from a neighbor cell during the idle periods.

[0036] In a positioning through the OTDOA method, the accuracy of the
measurement is based on 1) the number of base stations (or cells), which
can receive an RS (or a pilot) discriminated by a UE (or MS) (the number
should be more than three and the accuracy may be increased as the number
of base stations is increased), 2) a relative location of a base station
(the accuracy may be increased when the base station is located in a
different direction from a UE), and 3) a line-of-sight (when the UE and
the base station are location in line-of-sight from each other, the
accuracy may be increased). That is, when a UE or a base station on each
network receives a RS (or a pilot) from a neighbor cell, the UE or the
base station should be able to discriminate RSs transmitted from neighbor
cells to receive the discriminated RSs. When the number of distinct RSs
is increased and the performance of the RSs is improved, the three
considerations may be satisfied. In other words, as the number of base
station (cell)-specific RSs (or pilots), which have distinct excellent
performances, is increased, 1) the number of base stations, which can be
received, is increased, 2) a possibility that at least three base
stations, which are positioned in a relatively better location, can be
selected among the base stations is stochastically increased, and 3) a
possibility that at least three base stations, which are positioned in a
relatively better lint-of-sight, can be selected among the base stations
is stochastically increased, so that a correct location information may
be obtained through a more accurate OTDOA measurement.

[0037] An LTE system advanced from WCDMA affiliated with 3GPP is based on
an OFDM (Orthogonal Frequency Division Multiplexing) unlike asynchronous
CDMA (Code Division Multiple Access) scheme of WCDMA. As the positioning
performed through an OTDOA method in the WCDMA, a new LTE system
considers the positioning performed based on the OTDOA method.
Accordingly, a method is considered in which data regions, which are the
remaining regions except control regions for existing Reference Signals
(RSs) and control channels, are reserved on a regular period in one of an
MBSFN (Multicast Broadcast Single Frequency Network) subframe structure
and a normal subframe structure, or each subframe structure of both
subframes and then reference signals for the positioning is transmitted
to the reserved regions in the subframes. That is, for the positioning in
an LTE, which is a new next generation communication method based on the
OFDM method, a method of transmitting reference signals for the
positioning and constructing the reference signals in a new resource
allocation structure should be reconsidered since a communication
infrastructure has been changed from an existing asynchronous CDMA-based
WCDMA method to OFDM-based multiplexing method and access method.
Further, a more accurate positioning method is required by the
development of a communication system such as an increase in a movement
velocity of a UE, a change in an interference environment between base
stations, and an increase in complexity.

[0038] An embodiment of the present invention provides a method of
generating a positioning reference signal pattern by using the modular
sonar sequence.

[0039] In accordance with an aspect of the present invention, there is
provided a method of generating a positioning reference signal pattern
for positioning a User Equipment (UE) in a wireless communication system,
the method including generating a first M×N modular sonar sequence
based on M and N corresponding to determined modular sonar sequence
sizes, converting the generated first M×N modular sonar sequence to
a second M×N modular sonar sequence according to system-specific
information, and forming a positioning reference signal pattern from the
second M×N modular sonar sequence and mapping positioning reference
signals.

[0040] In accordance with another aspect of the present invention, there
is provided a method of generating a positioning reference signal pattern
for positioning a User Equipment (UE) in a wireless communication system,
the method including generating a first M×N modular sonar sequence
based on M and N corresponding to determined modular sonar sequence
sizes, generating a first M×(N-N') modular sonar sequence by
truncating an end part having a length N' out of the generated first
M×N modular sonar sequence having a length N, converting the first
M×(N-N') modular sonar sequence to a second M×(N-N') modular
sonar sequence according to system-specific information, and forming a
positioning reference signal pattern from the second M×(N-N')
modular sonar sequence and mapping positioning reference signals.

[0041] In accordance with another aspect of the present invention, there
is provided a method of generating a positioning reference signal pattern
for positioning a User Equipment (UE) in a wireless communication system,
the method including generating a first M×N modular sonar sequence
based on M and N corresponding to determined modular sonar sequence
sizes, converting the generated first M×N modular sonar sequence to
a second M×N modular sonar sequence according to system-specific
information, generating a second M×(N-N') modular sonar sequence by
truncating an end part having a length N' out of the second M×N
modular sonar sequence having a length N, and forming a positioning
reference signal pattern from the second M×(N-N') modular sonar
sequence and mapping positioning reference signals.

[0042] In accordance with another aspect of the present invention, there
is provided an apparatus for generating a positioning reference signal
pattern for positioning a User Equipment (UE) in a wireless communication
system, the apparatus including an M×N modular sonar sequence
generator for generating a first M×N modular sonar sequence based
on M and N corresponding to determined modular sonar sequence sizes, and
converting the generated first M×N modular sonar sequence to a
second M×N modular sonar sequence according to system-specific
information, and a positioning reference signal mapper for forming a
positioning reference signal pattern from the second M×N modular
sonar sequence and mapping positioning reference signals.

[0043] In accordance with another aspect of the present invention, there
is provided an apparatus for generating a positioning reference signal
pattern for positioning a User Equipment (UE) in a wireless communication
system, the apparatus including an M×N modular sonar sequence
generator for generating a first M×N modular sonar sequence based
on M and N corresponding to determined modular sonar sequence sizes, an
M×(N-N') modular sonar sequence generator for generating a first
M×(N-N') modular sonar sequence by truncating an end part having a
length N' out of the generated first M×N modular sonar sequence
having a length N, and converting the first M×(N-N') modular sonar
sequence to a second M×(N-N') modular sonar sequence according to
system-specific information, and a positioning reference signal mapper
for forming a positioning reference signal pattern from the second
M×(N-N') modular sonar sequence and mapping positioning reference
signals.

[0044] In accordance with another aspect of the present invention, there
is provided an apparatus of generating a positioning reference signal
pattern for positioning a User Equipment (UE) in a wireless communication
system, the apparatus including an M×N modular sonar sequence
generator for generating a first M×N modular sonar sequence based
on M and N corresponding to determined modular sonar sequence sizes, an
M×(N-N') modular sonar sequence generator for converting the
generated first M×N modular sonar sequence to a second M×N
modular sonar sequence according to system-specific information, and
generating a second M×(N-N') modular sonar sequence by truncating
an end part having a length N' out of the second M×N modular sonar
sequence having a length N, and a positioning reference signal mapper for
forming a positioning reference signal pattern from the second
M×(N-N') modular sonar sequence and mapping positioning reference
signals.

[0045] Specifically, the present invention provides an effective method of
constructing a reference signal for the positioning in a new resource
allocation structure where a communication infrastructure is changed from
an existing asynchronous CDMA-based WCDMA method to OFDM-based
multiplexing method and access method in detecting a UE (User Equipment)
location through a reference signal (or a pilot) for the positioning in
an OTDOA (Observed Time Difference Of Arrival) manner in the OFDM
(Orthogonal Frequency Division Multiplexing)-based wireless mobile
communication system. Particularly, the present invention provides
excellent PRS (Positioning Reference Signal) patterns in an aspect of the
number of distinct cell-specific patterns and the performance for more
accurate positioning method required by the development of a
communication system such as an increase in a movement velocity of a UE,
a change in an interference environment between base stations, and an
increase in complexity.

[0046] Accordingly, the present invention considers a method of generating
a positioning reference signal according to the requirements based on the
modular sonar sequence.

[0047] The modular sonar sequence described herein is first discussed
below.

[0048] For integers m and n, M={1, 2, . . . , m} and N={1, 2, . . . , n}
(where, M is a set including values generated by modulo m of integers).
For all integers h, i, and j where 1≦h≦n-1, 1≦i, and
j≦n-h, when i=j from f(i+h)-f(i)=f(j+h)-f(j) (mod m), a function
f: N→M has a difference property discriminated by a modular
(hereinafter, referred to as a "distinct modular differences property").

[0049] At this time, an M×N modular sonar sequence corresponds to
the function f: N-*M having the "distinct modular differences property".

[0050] For example, a sequence {1, 3, 7, 4, 9, 8, 6, 2, 5, 11(=0)} may be
a 11×10 modular sonar sequence having a value of "11" as a modular.

[0051] There are various methods of generating modular sonar sequences.
Table 1 below summarizes and illustrates all methods of generating the
modular sonar sequence known today according to a length, a range, and
modulo value. Detailed methods of generating the modular sonar sequence
in each method correspond to from generation method-A to generation
method-G.

[0058] 7) Generation method-G (Shift sequence): Suppose p is a prime
number and a and b are primitive elements on GF(p2r) and
GF(pr), respectively. Here, when p is 2, a function f: {1, 2, . . .
, pr}→{1, 2, . . . , pr-1} is defined as
f(i)=logb((ai)p.sup.λr+ai=Tr2rr(-
ai), and bf(i)=(ai)p
r+ai=Tr2rr(ai). When p is an odd number, the function
f corresponds to a (pr-1)×pr modular sonar sequence where
the function f is defined similarly as a case when p is 2, but a range of
i is {i: -(pr-1)/2≦i≦(pr-1)/2}.

[0059] The sequence {1, 3, 7, 4, 9, 8, 6, 2, 5, 11} described above as an
example is generated by cyclic-shifting a sequence {2, 4, 8, 5, 10, 9, 7,
3, 6, 1} by -1, and the 11×10 modular sonar sequence {2, 4, 8, 5,
10, 9, 7, 3, 6, 1} may be constructed by the Exponential Welch method (a
detailed generation method may be drawn from a case where a is 2 in
generation method-B (Exponential Welch)) in table 1. As shown in table 1,
a modular M has a value of "11" which is a prime number, and a length L
has a value of "10" which is obtained by 11-1.

[0060] M×N modular sonar sequences may be converted to different
M×N modular sonar sequences through three transformations.

[0061] First, when an original generated M×N modular sonar sequence
is f(i), 1≦i≦N (or 0≦i≦N-1), a is added to
f(i) for modulo m. The above function is represented as equation 1 below.

f.sub.+a(i)=f(i)+a (mod m) (1)

[0062] Equation 1 indicates that a row of a modular sonar array
(representing a modular sonar sequence as a two-dimension having a row
and a column) is cyclic-rotated in the unit of a. That corresponds to all
cyclic shifts in a frequency side of a sequence pattern one to one in a
two-dimension pattern of a time/frequency.

[0063] Second, when the original generated M×N modular sonar
sequence is f(i), 1≦i≦N (or 0≦i≦N-1), u is
multiplied by f(i) for modular m. The above function is represented as
equation 2 below.

f.sub.×u(i)=uf(i) (mod m) (2)

[0064] Equation 2 refers to a permutation of rows of the modular sonar
array. When a is "0", that corresponds to all cyclic shifts in a time
side of a sequence pattern one to one in a two-dimension pattern of a
time/frequency.

[0065] Third, when the original generated M×N modular sonar sequence
is f(i), 1≦i≦N (or 0≦i≦N-1), f(i) is sheared
in the unit of s for modulo m. The above function is represented as
equation 3 below.

fshear(s)(i)=f(i)+si (mod m) (3)

[0066] Equation 3 indicates that columns of the modular sonar array are
sheared in the unit of s.

[0067] In short, the function f corresponds to the M×N modular sonar
sequence. If u is the unit of the modular m, g may be defined as equation
4 below, and g also corresponds to the M×N modular sonar sequence.

g(i)=uf(i)+si+a (mod m) (4)

[0068] The present invention forms a pattern of a Positioning Reference
Signal (PRS) by using the modular sonar sequence.

[0069] A method of forming the pattern of the PRS by using the modular
sonar sequence according to an aspect (first aspect) of an embodiment of
the present invention is described below.

[0070] a. Modular sonar sequence sizes M and N are determined from
combinations capable of using as many available rows and columns as
possible from Ms and Ns combinable in table 1 and in consideration of
numbers of rows and columns available for positioning reference signals
in a two dimensional single subframe structure having a frequency axis (a
symbol axis in an OFDM structure) and a time (a subcarrier axis in an
OFDM structure) axis for each subframe (e.g. an MBSFN subframe, a normal
subframe with a normal CP, and a normal subframe with an extended CP).

[0071] b. Based on the selected M and N, the M×N modular sonar
sequence is generated by the construction method illustrated in table 1.

[0072] c. According to the generated modular sonar sequence, positioning
reference signals in a two dimensional single subframe structure having a
frequency axis (a symbol axis in an OFDM structure) and a time (a
subcarrier axis in an OFDM structure) axis for each subframe are mapped
to rows and columns available for the positioning reference signals.

[0073] For example, when the generated M×N modular sonar sequence is
{a, b, c, . . . , j, . . . }, {(x,y)|(x--1,y--1)=(1,a),
(x--2,y--2)=(2,b), (x--3,y--3)=(3,c), . . . ,
(x_i,y_i)=(i,j), . . . }, and an ith sequence value of the PRS is mapped
to a position where an xth (or yth) available column (symbol axis) and a
yth (or xth) available row (subcarrier axis) intersect. In other words,
when the ith sequence value of the generated M×N modular sonar
sequence is f(i)=j, the ith sequence value of the PRS for the subframe is
mapped to a position where an ith available column (symbol axis) and a
f(i)th available row (subcarrier axis) intersect, or a position where a
f(i)th available column (symbol axis) and an ith available row
(subcarrier axis) intersect.

[0074] d. Different PRS sequence patterns required for each base station
(or cell), each relay node, or each UE (or MS) are generated through the
following methods.

[0075] When the M×N modular sonar sequence generated through one
method in table 1 corresponds to f(i), 1≦i≦N (or
0≦i≦N-1), f(i) may be changed to the following three
functions.

[0076] Addition by a modulo m, f.sub.+a(i)=f(i)+a (mod m)

[0077] Multiplication by a unit u modulo m, f.sub.×i(i)=uf(i) (mod
m)

[0078] Shearing by s modulo m, fshear(s)(i)=f(i)+si (mod m)

[0079] By adding the three changed functions together, a new M×N
modular sonar sequence corresponding to a function g(i), which is
g(i)=uf(i)+si+a (mod m), 1≦i≦N (or 0≦i≦N-1),
may be generated. Through the new M×N modular sonar sequence,
sequence patterns of different PRSs may be generated.

[0080] At this time, a, u, and s may be determined by a function according
to a base station (or cell), a relay node, a UE (or MS), or other
specific information (a subframe number, a CP (Cyclic Prefix) size,
etc.). Particularly, it can be seen that different patterns for each base
station (or cell) (cell-specific patterns) may be generated from the fact
that u, s, and a may be determined according to base station (or cell)
information.

[0081] The above steps may be implemented by the apparatus illustrated in
FIG. 1. The apparatus for forming the pattern of the PRS by using the
modular sonar sequence largely includes an M×N modular sonar
sequence generator 110 and a PRS mapper 120. The M×N modular sonar
sequence generator 110 generates the modular sonar sequence and sizes M
and N of the generated modular sonar sequence are determined through a
modular sonar sequence size (M, N) determinator 112. Each modular sonar
sequence generated through the M×N modular sonar sequence generator
110 is specifically determined for each base station (or cell) according
to different parameter values determined by a system-specific information
(cell-specific information) mapper 114.

[0082] A detailed operation for each apparatus is described below. The
modular sonar sequence size (M, N) determinator 112 performs a function
corresponding to step a in the method of generating the pattern of the
PRS by using the modular sonar sequence according to the aspect of the
embodiment of the present invention. That is, numbers of rows and columns
available for position reference signals in a two dimensional single
subframe structure having a frequency axis and a time axis for each
subframe are calculated, and M and N are determined from combinations
capable of using as many available rows and columns as possible from Ms
and Ns combinable in table 1. The M×N modular sonar sequence
generator 110 first generates M×N modular sonar sequence f(i),
1≦i≦N (or 0≦i≦N-1) according to the
construction method illustrated in table 1 based on the sizes of M and N
determined through the modular sonar sequence size (M, N) determinator
112. Subsequently, the system-specific information mapper 114 receives
different parameter values of a, u, and s determined as a function
according to a base station (or cell), a relay node, a UE (or MS) or
other specific information (a subframe number, a CP (Cyclic Prefix) size,
etc.), and then generates the M×N modular sonar sequence
represented as different specific patterns for each system (particularly,
for each base station (or cell)) (cell-specific pattern), which
corresponds to g(i) that is g(i)=uf(i)+si+a (mod m), 1≦i≦N
(or 0≦i≦N-1). A PRS mapper 120 maps a PRS to a row and a
column available for the PRS in one subframe structure constructing a
two-dimensional structure including a time axis (symbol in an OFDM
structure) and a frequency axis (subcarrier in an OFDM structure)
according the M×N modular sonar sequence g(i), 1≦i≦N
(or 0≦i≦N-1) generated through the M×N modular sonar
sequence generator 110. That is, if an ith sequence value of the
generated M×N modular sonar sequence is g(i)=j, the ith sequence
value of the PRS for the subframe is mapped to a position where an ith
available column (symbol axis) and a g(i)th available row (subcarrier
axis) intersect and a position where a g(i)th available column (symbol
axis) and an ith available row (subcarrier axis) intersect.

[0083] The method of generating the pattern of the PRS according to the
present invention can generate a flexible pattern size. That is, since
the method can variously select M and N in generating the M×N
sequence, the method can flexibly apply pattern sizes.

[0084] The modular sonar sequence may be applied to various cases due to
various cases of parameters of M and N.

[0085] For example, an MBSFN (Multicast Broadcast Single Frequency
Network) subframe has a no-transmission region of 12 subcarriers×10
symbols excluding a control region. Applicable values of M and N, an
available frequency (subcarrier) and a time (symbol) size may be
generated in consideration of a size of the two-dimensional
no-transmission region for the subframe for the positioning and a case
where parameters of M and N are available as illustrated in table 1. For
example, in the MBSFN subframe, a size M×N is determined as 11
(subcarriers)×10 (symbols) through "Exponential Welch" method and
10 (symbols)×11 (subcarriers), and the modular sonar sequence may
be generated through the sizes.

[0086] When 11 (subcarriers)×10 (symbols) is selected as the size
M×N through "Exponential Welch" method of table 1, modulo M has a
value of "11" and a length N has a value of "10". That is, M=11 is used
for 11 available frequency horizontal axes among a total of 12
frequencies (subcarriers) of the horizontal axis in an MBSFN subframe of
a two-dimensional time/frequency pattern. N=10 is used for 10 available
time (symbol) vertical axes among a total of 10 times (symbols) of the
vertical axis in the MBSFN subframe.

[0087] The M×N modular sonar sequence may be extended to very
various two-dimensional sequence patterns discriminated by
g(i)=uf(i)+si+a (mod m).

[0088] At this time, the determined M×N modular sonar sequence may
be extended to the M×M×Ωc(M) number of distinct
PRS patterns through g(i)=uf(i)+si+a (mod m).

[0089] Here, Ωc(M) is defined as equation 5 below.

Ωc(M)=n(u={i|1≦i<M, gcd(i,M)=1}) (5)

[0090] In equation 5, gcd is the greatest common divisor.

[0091] Each of patterns included in the determined g(i),
1≦i≦N (or 0≦i≦N-1) has "minimum ambiguity".
That is, although the original PRS pattern is cyclic-shifted (or is time
or/and frequency delayed in an aspect of the system) in a time axis
or/and a frequency axis, the maximum number of overlapped PRS symbols (or
PRS sequence symbols, PRS sequence elements, or resource elements from an
aspect of an OFDM-based resource allocation structure) is "1" ("0" or
"1"), and a larger number of PRS patterns or a PRS pattern having a
higher reuse factor may be additionally generated.

[0092] The method of forming the PRS pattern by using the modular sonar
sequence according to another aspect (second aspect) of the embodiment of
the present invention will now be described.

[0093] a. In consideration of a larger value between the number of
available rows and the number of columns for positioning reference
signals in a two dimensional single subframe structure having a frequency
axis (a symbol axis in an OFDM structure) and a time (a subcarrier axis
in an OFDM structure) axis for each subframe (e.g. an MBSFN subframe, a
normal subframe with a normal CP, and a normal subframe with an extended
CP), the value is determined as M.

[0094] b-1. Based on the selected M, the M×N modular sonar sequence
is generated by the construction method illustrated in table 1. At this
time, when M=N from the M×N sequence, that is, a modular sonar
sequence of N×N corresponds to an N×N modular sonar sequence
and an N×N modular (or perfect) costas array.

[0095] b-2. When it is determined that a larger value is M and a smaller
value is (N-N') betweem the number of available rows and the number of
available columns for the PRS in the subframe structure, an
M×(N-N') modular sonar sequence is generated by truncating an end
of the M×N modular sonar sequence by N' where N is a length
generated through b-1.

[0096] c/d. It is the same as step c/d according to the previous aspect of
the embodiment of the present invention. However, in the previous aspect,
the M×N modular sonar sequence is used, but in this aspect, the
M×(N-N') modular sonar sequence is used. At this time, there are
two methods of generating a specific modular sonar sequence
(particularly, a base station (cell)-specific modular sonar sequence) for
each system from the M×N modular sonar sequence. In a first method,
the M×N modular sonar sequence is generated, the generated
M×N modular sonar sequence is converted according to
system-specific information, and then N' is truncated from the converted
M×N modular sonar sequence, so that the M×(N-N') modular
sonar sequence is generated. In a second method, the M×N modular
sonar sequence is generated, and N' is truncated from the generated
M×N modular sonar sequence, so that the M×(N-N') modular
sonar sequence is generated. Then, the generated M×(N-N') modular
sonar sequence is converted to a system-specific M×M×(N-N')
modular sonar sequence according to system-specific information.

[0097] The method according to another aspect (second aspect) of the
embodiment of the present invention may be implemented by an apparatus of
FIG. 9. According to the present invention, another apparatus for
generating the pattern of the PRS by using the modular sonar sequence
largely includes an M×N modular sonar sequence generator 610, an
M×(N-N') modular sonar sequence generator 620, and a PRS mapper
630. The M×N modular sonar sequence generator 610 generates the
modular sonar sequence and sizes M and N of the generated modular sonar
sequence are determined through a modular sonar sequence size (M, N)
determinator 612. The M×(N-N') modular sonar sequence generator 620
generates the M×(N-N') modular sonar sequence by truncating an end
of the generated M×N modular sonar sequence by N'. At this time,
the M×N modular sonar sequence is specifically determined for each
base station (cell) (cell-specific) according to different parameter
values determined according to a system-specific information
(cell-specific information) mapper 622, and then an end of the converted
M×N modular sonar sequence is truncated by N', so that the
M×(N-N') modular sonar sequence may be generated, or the end of the
converted M×N modular sonar sequence is first truncated by N' and
then the M×(N-N') modular sonar sequence is specifically determined
for each base station (cell) (cell-specific) according to different
parameter values.

[0098] A detailed operation for each apparatus is described below. The
modular sonar sequence size (M, N) determinator 612 calculates a larger
value of the number of available rows and the number of available columns
for the PRS in one subframe structure, and then determines the larger
value as M. Based on selected value of M, the M×N modular sonar
sequence generator 610 generates the M×N modular sonar sequence
through the construction method in table 1. When it is determined that a
larger value is M and a smaller value is (N-N') among the number of
available rows and the number of available columns for the PRS in the
subframe structure, the M×(N-N') modular sonar sequence generator
620 generates the M×(N-N') modular sonar sequence by truncating an
end of the M×N modular sonar sequence generated by the M×N
modular sonar sequence generator 610 by N' where N is a length of the
modular sonar sequence. At this time, as described above, the M×N
modular sonar sequence is specifically determined for each base station
(cell) (cell-specific) according to different parameter values determined
according to the system-specific information (cell-specific information)
mapper 622, and then an end of the M×N modular sonar sequence is
truncated by N', so that the M×(N-N') modular sonar sequence may be
generated, or the end of the converted M×N modular sonar sequence
is first truncated by N' and then the M×(N-N') modular sonar
sequence is specifically determined for each base station (cell)
(cell-specific) according to different parameter values. At this time,
the system-specific information mapper 622 receives different parameter
values of a, u, and s determined as a function according to a base
station (or cell), a relay node, a UE (or MS) or other specific
information (a subframe number, a CP (Cyclic Prefix) size, etc.), and
then generates the modular sonar sequence represented as different
specific patterns for each system, particularly, for each base station
(cell-specific patterns), which corresponds to g(i) that is
g(i)=uf(i)+si+a (mod m), 1≦i≦N (or 0≦i≦N-1).
The PRS mapper 620 maps a PRS to a row and a column available for the PRS
in one subframe structure constructing a two-dimensional structure
including a time axis (symbol in an OFDM structure) and a frequency axis
(subcarrier in an

[0099] OFDM structure) according the M×(N-N') modular sonar sequence
g(i), 1≦i≦N-N' (or 0≦i≦(N-N')-1) generated
through the M×(N-N') modular sonar sequence generator 620. That is,
if an ith sequence value of the generated M×(N-N') modular sonar
sequence is g(i)=j, the ith sequence value of the PRS for the subframe is
mapped to a position where an ith available column (symbol axis) and a
g(i)th available row (subcarrier axis) intersect and a position where a
g(i)th available column (symbol axis) and an ith available row
(subcarrier axis) intersect.

[0100] In the method (or apparatus) for forming the pattern of the PRS by
using the M×N modular sonar sequence according to the aspect (first
aspect) of the embodiment of the present invention, the M×N modular
sonar sequence may be extended to the M×M×Ωc(M)
number of different RPS patterns by g(i)=uf(i)+si+a (mod m). At this
time, a, u, and s are determined according to system information,
particularly, base station (or cell) information, so that different
patterns specific for each base station (cell) (cell-specific patterns)
may be generated. At this time, when all of PRS patterns do not have to
be used since the number of M×M×Ωc(M) PRS patterns
according to an aspect of the present invention is much more than the
number of specific-information pieces, which should be discriminated, the
method (or apparatus) according to the aspect of the present invention
may be changed to the following method (or apparatus).

[0101] A first method (or apparatus) determines a value of
"freq_shift_value, and a value of "time_shift_value" to be cyclic-shifted
in a frequency axis and a time axis according to system-specific
information, particularly, base station (or cell) information, and then
cyclic-shifts the generated M×N modular sonar sequence f(i),
1≦i≦N (or 0≦i≦N-1) by the values in a
frequency axis and a time axis. At this time, the number of values, which
can be cyclic-shifted in a frequency axis and a time axis, is M and N,
respectively, so that the M×N number of different system-specific
(particularly, base station (cell)-specific) PRS patterns may be
generated. That is, for example, when the Cell_ID_Group number of base
station (cell)-specific information pieces is to be discriminated, a
quotient and a remainder generated by dividing Cell_ID_Group by M (or N)
are obtained, and the quotient and the remainder are determined as the
value of "freq_shift_value, and the value of "time_shift_value" to be
cyclic-shifted in a frequency axis and a time axis, respectively. For
example, when 12×12 modular sonar sequence is used, the maximum
number of distinct base station (cell)-specific information pieces is
144. At this time, when Cell_ID_Group=T≦144 and
0≦t≦T-1, it is determined that a quotient is
"freq_shift_value(=(t-(t mod 12))/12=.sup..left brkt-bot.t/12.right
brkt-bot.)" and a remainder is "`time_shift_value(=t mod 12)" by dividing
T by 12. In contrast, when it is determined that a quotient is
"`time_shift_value(=t mod 12)" and a remainder is
"freq_shift_value(=(t-(t mod 12))/12=.sup..left brkt-bot.t/12.right
brkt-bot.)", a cyclic-shift is performed in a frequency axis by
"freq_shift_value" and in a time axis by "`time_shift_value". That is
represented as an equation below. When f0(i),
0≦i<N(f(0)=f(N)) corresponds to the M×N modular sonar
sequence generated in advance and an ith (0≦t<T) M×N
modular sonar sequence to be converted through a frequency/time axis
cyclic-shift is ft(i), 0≦i<N, ft(i), 0≦i<N
may be represented as equation 6 below.

[0102] A second method (or apparatus) constructs PRS patterns only with
patterns, which are not overlapped at all, among the
M×M×Ωc(M) number of patterns by the M×N
modular sonar sequence, and generates specific PRS patterns for each
system, particularly for each base station (cell) through a 1:1
correspondence table between the patterns and system-specific
(particularly base station (cell)-specific) information. For example,
when the M×M×Ωc(M) number of PRS patterns is
generated, some of the patterns are not overlapped at all (0 overlapped
patterns) and one pattern of the remaining patterns is overlapped (1
overlapped pattern). When the number of not overlapped patterns is "X", a
1:1 correspondence table between the maximum "X" number of patterns and
the "X" number of base station numbers (cell_ID) is generated and the
maximum "X" number of base station (cell)-specific PRS patterns may be
generated through the 1:1 correspondence table.

[0103] Two changes of the step of generating different system-specific
(particularly base station (cell)-specific) PRS patterns in the method
(or apparatus) for forming the pattern of the PRS by using the M×N
modular sonar sequence according to the aspect of the embodiment of the
present invention may be identically applied to the method (or apparatus)
for forming the PRS pattern by using the M×(N-N') modular sonar
sequence in the same manner according to another aspect of the present
invention.

[0104] The method of forming the pattern of the PRS by using the modular
sonar sequence according to still another aspect (third aspect) of the
embodiment of the present invention first calculates the number of
available time (symbol) axes (the number is determined as M or N), and a
maximum size of M×N modular sonar sequence, which may be combined
from table 1, may be generated based on the number of available time
(symbol) axes. For example, in a MBSFN subframe, the number of available
time (symbol) axes is 10 and thus it is possible to generate the
11×10 modular sonar sequence.

[0105] Accordingly, the maximum number of available frequency (subcarrier)
axes may be obtained. In the MBSFN subframe, the number is 11. The number
of 11 is considered as the total number of frequency (subcarrier) axes
and mapped as a period. That is, when the PRS pattern is repeated every
12 subcarriers on a frequency axis in the aspect and another aspect of
embodiments of the present invention (specifically, when 11 subcarriers
are used on a 12-subcarrier period), the PRS pattern is repeated every 11
subcarriers in still another aspect (third aspect) of the present
invention. That is, 11 subcarriers are used on a 11-subcarrier period.

[0106] Hereinafter, exemplary embodiments of forming the PRS pattern by
using the M×N modular sonar sequence according to an aspect of an
embodiment of the present invention are described in detail with
reference to FIGS. 2 to 8.

[0107] FIGS. 2 to 4 illustrate embodiments in an MBSFN subframe structure
of an LTE system.

[0108] Referring to FIG. 2, when available columns correspond to 10
symbols among 10 symbol axes as a time (or a symbol or column axis) and
available rows correspond to 11 subcarriers among 12 subcarrier axes as a
frequency (or a subcarrier or row axis), the 11×10 modular sonar
sequence is generated through "Exponential Welch" method of table 1.

[0109] The sequence generated through "Exponential Welch" method
corresponds to {2, 4, 8, 5, 10, 9, 7, 3, 6, 1 }, and is mapped in the
manner of FIG. 2. (In FIG. 2, a first PRS pattern is formed in a position
where an available first row (symbol axis) and a second subcarrier axis
from the bottom corresponding to a second subcarrier axis intersect, on
an assumption that the bottom subcarrier axis is a first subcarrier axis
in a subframe structure as shown in FIG. 2. However, when it is assumed
that the bottom subcarrier axis is a zeroth subcarrier axis, the first
PRS pattern is formed in a position where the available first row (symbol
axis) and a third subcarrier axis from the bottom corresponding to the
second subcarrier axis intersect. In this case, total RPS patterns are
mapped such that the PRS patterns are upward cyclic-shifted by 1 in a
subcarrier (frequency) axis from the signal patterns shown in FIG. 2.) In
FIG. 2, 11 subcarrier axes excluding a twelfth subcarrier axis are used
as available axes and certain 11 rows among 12 rows may be selected as
available rows.

[0110] Different PRS sequence patterns are generated by g(i)=uf(i)+si+a,
and then inherent PRS patterns for each system-specific information
(particularly base station (cell)-specific information) may be generated.
Further, the PRS patterns may be generated through a simple cyclic shift
in a time/frequency axis.

[0112] As another example, the sequence {1, 2, 4, 8, 5, 10, 9, 7, 3, 6}
corresponds to a case where the sequence {2, 4, 8, 5, 10, 9, 7, 3, 6, 1}
is cyclic-shifted by 1 in a time axis, and may be mapped in a manner of
FIG. 4.

[0113] In the 11×10 modular sonar sequence, the generation of the
11×11×10=1210 number of inherent patterns may be expected. At
this time, when 1210 patterns are not required since the number 1210 is
too much, 11×10=110 different PRS patterns may be generated only
through a cyclic-shift of the generated patterns in a frequency axis and
a time axis according to system-specific information. Further, by
selecting only patterns, which are not overlapped at all, among the
patterns, a 1:1 correspondence table between the patterns and
system-specific (particularly base station (cell)-specific) information
is generated and specific-PRS patterns for each system (particularly for
each base station (cell)) may be generated through the 1: 1
correspondence table.

[0114] FIG. 5 illustrates embodiments in a normal subframe structure
having a normal CP (Cyclic Prefix) of an LTE system.

[0115] Referring to FIG. 5, in the normal subframe having the normal CP, a
no-transmission region except a control region corresponds to 12
(subcarriers)×12 (symbols). When an additional 3 time vertical (or
column) axes for CRS are considered as non-available vertical (or column)
axes, 10 (subcarriers)×9 (symbols) by the "Lempel" method or the
"Colomb" method of table 1 may be an embodiment of the present invention.
The subframe structure of FIG. 5 is an example of a 10
(subcarriers)×9 (symbols) structure by the "Lempel" method. A
10×9 modular sonar sequence {5, 3, 2, 7, 1, 8, 4, 6, 9} by the
"Lempel" method may be mapped as shown in FIG. 5. At this time, distinct
patterns having 400 "minimum ambiguity" which is obtained by
10×10×4 may be generated. Available columns correspond to 9
symbols among 12 symbol axes as a time (or a symbol or column axis) and
available rows correspond to 10 subcarriers among 12 subcarrier axes as a
frequency (or a subcarrier or row axis), and the 10×9 modular sonar
sequence is generated.

[0116] At this time, the pattern is generated by selecting only certain 10
subcarrier axes among total 12 subcarrier axes. In embodiments of FIG. 5,
2 frequency horizontal axes from the top among 4 frequency horizontal
axes including CRS are selected as non-available frequency horizontal (or
row) axes.

[0117]FIG. 6 illustrates embodiments in a normal subframe structure
having an extended CP of an LTE system.

[0118] Referring to FIG. 6, in the normal subframe structure having an
extended CP, a no-transmission region except a control region corresponds
to 12 (subcarriers)×10 (symbols). When an additional 3 time
vertical (or column) axes for CRS are considered as non-available
vertical (or column) axes, 8 (subcarriers)×7 (symbols) by the
"Lempel" method or the "Colomb" method or 7 (subcarriers)×8
(symbols) by the "Quadratic" method of table 1 may be embodiments of the
present invention. The subframe structure of FIG. 6 is an example of an 8
(subcarriers)×7 (symbols) structure by the "Lempel" method. An
8×7 modular sonar sequence {2, 1, 6, 4, 7, 3, 5} by the "Lempel"
method may be mapped as shown in FIG. 6. At this time, distinct patterns
having 256 "minimum ambiguity" which is obtained by 8×8×4 may
be generated. Available columns correspond to 7 symbol axes among 10
symbol axes as a time (or a symbol or column axis) and available rows
correspond to 8 subcarrier axes among 12 subcarrier axes as a frequency
(or a subcarrier or row axis), and the 8×7 (or 7×8) modular
sonar sequence is generated.

[0119] At this time, the pattern is generated by selecting only a certain
8 subcarrier axes among total 12 subcarrier axes. In embodiments of FIG.
6, 4 frequency horizontal axes including CRS are selected as
non-available frequency horizontal (or row) axes.

[0120] FIGS. 7 and 8 illustrate another embodiment in the normal subframe
structure having the extended CP of an LTE system.

[0121] Referring to FIG. 7, available columns correspond to 7 symbol axes
among 10 symbol axes as a time (or a symbol or column axis) and available
rows correspond to 6×2=12 subcarrier axes among 12 subcarrier axes
as a frequency (or a subcarrier or row axis), and they may be constructed
by two 7×6 modular sonar sequences.

[0122] Through the two 7×6 modular sonar sequences, 12 subcarrier
axes are divided into two groups each having 6 subcarriers, and each
sequence is mapped to each group. As shown in the example of the
structure of FIG. 7, the first 6 subcarrier axes may be a first group and
the rest 6 subcarrier axes may be a second group or even number (or odd
number) subcarrier axes may be a first group and the rest of odd number
(or even number) subcarrier axes may be a second group.

[0123] Referring to FIG. 8, the pattern of the PRS in the normal subframe
structure having the extended CP of an LTE system includes two 7
(symbols)×6 (subcarriers) modular sonar sequences. At this time, a
7×6 sequence {3, 6, 1, 5, 4, 2} by the "Lempel" method and a
7×6 sequence {6, 4, 2, 5, 7, 3} by the "Colomb" method are mapped
as the PRS pattern of an embodiment of the FIG. 8.

[0124] At this time, a method of mapping the 7 (symbols)×6
(subcarriers) modular sonar sequence in FIG. 8 is different from a
general method of mapping M (subcarriers)×N (symbols). In a M
(subcarriers)×N (symbols) modular sonar sequence g(i),
1≦i≦N (or 0≦i≦N-1), when an ith sequence
value of the M (subcarriers)×N (symbols) modular sonar sequence is
g(i)=j, the ith sequence value of the PRS for the subframe is mapped to a
position where an ith available column (symbol axis) and a g(i)th
available row (subcarrier axis) intersect. However, in a M
(symbols)×N (subcarriers) modular sonar sequence g(i),
1≦i≦N (or 0≦i≦N-1) like 7 (symbols)×8
(subcarriers) in FIG. 8, the ith sequence value of the PRS for the
subframe is mapped to a position a position where a g(i)th available
column (symbol axis) and an ith available row (subcarrier axis)
intersect.

[0125] Hereinafter, exemplary embodiments for forming the pattern of the
PRS by using the M×(N-N') modular sonar sequence according to
another aspect of an embodiment of the present invention are described in
detail with reference to FIGS. 7 and 8.

[0126] As described above, when the M×N modular sonar sequence is
generated, M is considered as one largest value among available frequency
axes and time axes, and the PRS pattern may be generated. Here, referring
to that considered available frequency axes correspond to 12 subcarriers
and available time axes correspond to 10, 9, or 7 symbols in one subframe
structure, M is determined as 12 and a 12×N modular sonar may be
generated through a value of M. At this time, available values of N from
table 1 are 12 by the "Logarithmic Welch" method, 11 by the "Lempel"
method or "Golomb" method, and 13 by the "Shift sequence" method. That
is, an end of the sequence having a length of 12 (or 11, 13) may be
truncated by N' from a 12×12 (or 12×11, 12×13) modular
sonar sequence having the generated modular value of 12 and the length of
12 (or 11, 13). Finally, the M×(N-N') modular sonar sequence is
generated. For example, in an MBSFN subframe which can have a maximum of
12 available frequency (subcarrier) axes and 10 available time (symbol)
axes, an end of the sequence having a length of 12 (or 11, 13) is
truncated by 2 (or 1, 3). Finally, a 12 (frequency axes)×10 (time
axes) modular sonar sequence is generated. In a normal subframe having
the normal CP, an end of the sequence having a length of 12 (or 11, 13)
is truncated by 3 (or 2, 4) by using the same method. Finally, a 12
(frequency axes)×9 (time axes) modular sonar sequence is generated.
In a normal subframe having the extended CP, a 12 (frequency
axes)×7 (time axes) modular sonar sequence is generated. Although
an end of a sequence length is truncated, the performance is nearly the
same since the discernible "distinct modular differences property" is
almost maintained. However, there is an advantage in that a maximum
number of available frequency axes (12 frequency axes in the above
example) may be fully used.

[0127] For example, when the 12×12 modular sonar sequence is
generated by using the "Logarithmic Welch" method, a sequence {12(=0), 1,
4, 2, 9, 5, 11, 3, 8, 10, 7, 6} is generated. (In FIG. 10, a first PRS
pattern is formed in a position where an available first row (symbol
axis) and a twelfth subcarrier axis from the bottom corresponding to a
twelfth(=0th) subcarrier axis intersect, on an assumption that the bottom
subcarrier axis is a first subcarrier axis in a subframe structure as
shown in FIG. 10. However, when it is assumed that the bottom subcarrier
axis is 0th subcarrier axis, the first PRS pattern is formed in a
position where the available first row (symbol axis) and a 0th subcarrier
axis from the bottom corresponding to the twelfth(=0th) subcarrier
axis intersect. In this case, total RPS patterns are mapped such that the
PRS patterns are upward cyclic-shifted by 1 in a subcarrier (frequency)
axis from the signal patterns shown in FIG. 2.)

[0141] At this time, methods of generating different pattern of the
sequences generated in the embodiments may use g(i)=uf(i)+si+a (mod m) as
described above, use only cyclic-shifted patterns in a time/frequency
axis from the generated patterns, or select only patterns corresponding
to the 0 overlapped pattern among patterns generated through the two
methods and then use the selected patterns.

[0142] Further, when the cyclic-shifted patterns in a time/frequency axis
are used for the modular sonar sequence generated in the above
embodiments, the patterns are cyclic-shifted in both time and frequency
axes, or the patterns are fully cyclic-shifted in one axis of the time
axis and the frequency axis but the patterns are partially cyclic-shifted
in the other axis. In the latter case, as an example, the patterns are
fully cyclic-shifted in the frequency axis but the patterns are
cyclic-shifted only in one or two time axes, and then the PRS patterns
may be generated.

[0146] In equation 6, .left brkt-bot.t/M.right brkt-bot. is a quotient of
t/M and used for a cyclic-shift in a time axis. (t mod M) is a remainder
of t/M and used for a cyclic-shift in a frequency axis.

[0147] c. As illustrated in equation 7 below, a truncated M×(N-N')
modular sonar sequence ft(i)=ft(i) (0≦i<N-N') is
generated. Of course, there may be a case where the truncation is not
required, that is, N' has a value of "0".

ft'(i)=ft(i) for 0≦N-N' (7)

[0148] d. The PRS pattern is generated. In the PRS pattern in a
two-dimensional structure including M×(N-N') frequency
(subcarrier)/time (symbol) , a PRS pattern for an OTDOA positioning
subframe is formed in a position where an ith available symbol axis and a
ft(i)th available subcarrier axis intersect for 0≦i<N-N'
(0=N-N' mod (N-N')).

[0149] e. The PRS sequence is mapped to the PRS pattern of the generated
OTDOA positioning subframe.

[0150] As described above, the patterns may be cyclic-shifted in both the
time axis and the frequency axis, or the patterns are fully
cyclic-shifted in one axis of the time axis and the frequency axis but
the patterns are partially cyclic-shifted in the other axis. As an
example where the patterns are generated by cyclic-shifting the patterns
in all frequency axes and in two time axes, a case where the 12×12
modular sonar sequence is used without any change or used by truncating
the sequence is described. At this time, a cyclic-shift is possible in 12
frequency axes and 2 time axes so that 24 patterns may be generated.

[0153] b. A tth (0≦t<T=2M) M×N modular sonar sequence
ft(i)(0≦i<N) is generated by equation 8 below. When M=12,
T=24 and distinct 12×12 modular sonar sequences are generated. In
equation 8 below, k has values from 1 to 11. For example, when k=1, 2
time axes used for a cyclic shift correspond to cyclic shifting the
M×N modular sonar sequence in a time axis zero time and one time.
When k=6, the 2 time axes used for the cyclic shift correspond to cyclic
shifting the M×N modular sonar sequence in a time axis zero time
and six times.

[0154] In equation 8, .left brkt-bot.t/M.right brkt-bot. is a quotient of
t/M and used for a cyclic-shift in a time axis. (t mod M) is a remainder
of t/M and used for a cyclic-shift in a frequency axis.

[0155] c. A truncated M×(N-N') modular sonar sequence
ft(i)=ft(i) (0≦N-N') is generated by equation 7. Of
course, there may be a case where the truncation is not required, that
is, N' has a value of "0".

[0156] d. The PRS pattern is generated. In the PRS pattern in a
two-dimensional structure including M×(N-N') frequency
(subcarrier)/time (symbol) , a PRS pattern for an OTDOA positioning
subframe is formed in a position where an ith available symbol axis and a
ft(i)th available subcarrier axis intersect for
0≦i≦N-N' (0=N-N' mod (N-N)).

[0157] e. The PRS sequence is mapped to the PRS pattern of the generated
OTDOA positioning subframe.

[0158] A case where the PRS pattern is generated by cyclic-shifting the
PRS pattern in all frequency axes and 1 time axis, or only all frequency
axes is described as an example in which 12×12 modular sonar
sequence is used without any change or is used after the truncation. At
this time, the PRS pattern is generated by cyclic-shifting the PRS
pattern in all frequency axes so that 12 patterns may be generated.

[0161] b. A tth (0≦t<T=M) M×N modular sonar sequence
ft(i)(0≦N) is generated by equation 9 below. When M=12, T=12
and the 12 total number of distinct 12×12 modular sonar sequences
are generated.

ft(i)=(f0(i)+t) mod M, 0≦i< (9)

[0162] The rest c/d/e steps are identical to c/d/e steps of the method of
generating the 144 PRS patterns or the 24 PRS patterns.

[0163] Further, as described above, both the time axis and the frequency
axis may be fully cyclic-shifted, one axis of the time axis and the
frequency axis may be fully cyclic-shifted, or a part of the time axis
and/or a part of the frequency axis may be cyclic-shifted.

[0164] For example, 6 PRS sequences may be generated by cyclic-shifting
only a half (M/2) of the frequency axis from the original M×N
modular sonar sequence f0={f0(0), f0(1), f0(2),
f0(3), f0(4), f0(5), f0(6), f0(7), f0(8),
f0(9), f0(10), f0(11)}={12(=0), 1, 4, 2, 9, 5, 11, 3, 8,
10, 7, 6} where M=12 and N=12. A method is identical to the method of
generating the 12 PRS sequences, but there is only a difference in a
range of t where 0≦t<T=M/2. Further, in step d, the PRS pattern
for the OTDOA positioning subframe is formed in all positions where an
ith available symbol axis and a ((ft(i)+.left brkt-bot.M/2.right
brkt-bot.) mod M)th available subcarrier axis intersect as well as all
positions where an ith available symbol axis and a ft(i)th available
subcarrier axis intersect.

[0165] In the above examples, T is 144, 24, 12, and 6, respectively, and
corresponds to the total number of system-specific information which
should be discriminated. If system-specific information corresponds to a
base station (cell) ID, that is, a PCI (Physical Cell Identify), T may be
a value generated by multiplying all base station (cell) IDs by groups
corresponding to T. That is represented as equation 10 below, and T
corresponds to 144, 24, 12, and 6 in equation 10 like the above examples.

0≦t=NIDcell mod T<T (10)

[0166] For example, when T=144, that is, when the total number of patterns
is 144, equation 10 may be represented as 0≦t=NIDcell
mod 144<T. Here, NIDcell has a value of
0≦NIDcell<504 and corresponds to a PCI (Physical Cell
Identity).

[0167] In the above description, it has been discussed that the PRS
pattern is generated by cyclic-shifting the modular sonar sequence in
both the time axis and the frequency axis, fully in one axis of the time
axis and the frequency axis, or partially in the time axis and/or the
frequency axis. At this time, in general, an apparatus for generating the
PRS pattern by using the modular sonar sequence has the same basic
construction as that of the apparatus illustrated in FIG. 1 or 9, but
only a part of functions of forming the PRS pattern through the
aforementioned steps is different. Accordingly, a description for
apparatuses for implementing the functions is replaced with the detailed
description for the apparatus illustrated in FIG. 1 or 9.

[0168] In the embodiments, it has been described that the M×N
modular sonar sequence is used for generating the PRS pattern, but the
M×N modular sonar sequence according to the present invention may
be used for other reference signals other than the PRS, for example, a
particular signal inserted into a frequency domain grid for a frequency
domain channel estimation at regular or irregular intervals, a reference
signal which is a symbol, a reference symbol, or a pilot symbol. For
example, reference signals in an uplink transmission include a DM-RS
(DeModulation RS) and an SRS (Sounding RS). In a downlink transmission,
the M×N modular sonar sequence may be used in a permissible range
for generating patterns of a CRS (Cell-specific RS), an MBSFN RS, and a
UE-specific RS as the reference signal, and a CSI-RS (CQI-RS) as the
reference signal transmitted from a base station in order to enable a
user device (terminal) to obtain Channel Spatial Information (CSI) of a
central cell or neighbor cells. Of course, the M×N modular sonar
sequence may be used for all reference signals currently defined or to be
defined in the future, or all reference signals having a changed
definition.

[0169] Further, the M×N modular sonar sequence may be used for
forming patterns of all signals which a terminal or a base station
determines to transmit and receive in a specific time and frequency band
for a channel estimation, a position estimation, and a
transmission/reception of information for control information or a
scheduling required for a process of wireless communication between the
terminal and the base station. At this time, when a particular signal or
symbol is inserted into a two-dimensional domain grid of a time and a
frequency at regular or irregular intervals, the signal pattern
corresponds to a form in which the particular signal is inserted in a
two-dimensional region of a time and a frequency.

[0170] In the embodiments, it has been described that the M×N
modular sonar sequence may be used for forming the pattern of the
reference signals including the PRS, but one or more sequences having the
same characteristic as that of the aforementioned M×N modular sonar
sequence may be used for generating the pattern of the reference signal
including the PRS in the present invention. For example, as described in
the example, the M×N modular sonar sequence where M=N has the same
characteristic as that of the N X N modular (or perfect) costas array. In
this case, the modular sonar sequence includes the modular castas array.

[0171] Meanwhile, In the embodiments, methods of generating 144, 24, 12,
and 6 PRS patterns in one subframe has been described, but the methods
are only illustrative. Further, various numbers of PRS patterns are
generated according one subframe form and then the PRS patterns may be
used for the positioning of the OTDOA manner.

[0172] In the embodiments, the method of generating the PRS patterns with
different patterns, which are specific for each cell, by using the
modular sonar sequence based on one subframe has been described. However,
in one or more subframes of a radio frame including subframes, the
particular signal specific for each cell, for example, PRS patterns may
be generated by using the aforementioned modular sonar sequence.

[0173] Further, the particular signal specific for each cell, for example,
PRS patterns may be generated by using the aforementioned modular sonar
sequence in the particular number of subframes in every frame on a
particular frame period in an aspect of the frame.

[0174] Hereinafter, frame periods, on which the particular signals
specific for each cell, for example, PRS patterns are generated by using
the aforementioned modular sonar sequence in the particular number of
subframes and resource blocks of a corresponding frame, will be
described.

[0175] FIG. 16 illustrates structures of the frame in which the PRS
pattern is formed in one or more subframes and the subframe according to
still another embodiment of the present invention.

[0176] Referring to FIG. 16, a basic subframe structure may include one or
more PRS subframes on a particular period, for example, a period of 16,
32, 64, or 128 for the OTDOA positioning. Only 0.1% to 1% of subframes
among all subframes may be used for the OTDOA positioning in
consideration of an overhead. For example, when a 32 radio frame period
is selected, subframes for PRS are included on a 320 subframe (1 radio
frame=10 subframes) period and first 1 or 2 subframes may be used. When a
64 radio frame period is selected, subframes for the PRS are included on
a 640 subframe period and first 4 or 6 subframes may be used.

[0177] At this time, the subframe may include an MBSFN (Multicast
Broadcast Single Frequency Network) subframe, a normal subframe having a
normal CP (Cyclic Prefix), or a normal subframe having an extended CP of
a communication system, for example, an LTE system.

[0178] At this time, one constructed PRS subframe may use all BandWidths
(BWs) in a frequency axis, but embodiments of the present invention are
not limited thereto and may use a part of all BW.

[0179] That is, when the BW corresponds to 10 Mhz, there exist 50 resource
blocks in the BW. The constructed PRS pattern corresponds to one RB in a
frequency axis so that the one constructed PRS subframe may be used to
generate PRS subframes in a frequency axis. In this case, the generated
one PRS subframe pattern may be copied and then 50 PRS RBs having the
same patterns may be constructed in a frequency axis, or PRS RBs having
different patterns may be generated.

[0180] As described above, in a time axis, first 1, 2, 4, or 6 PRS
subframes may be used among 10 subframes included in a single radio frame
on a radio frame period of 16, 32, 64, or 128. At this time, the
remaining subframes other than the PRS subframe may be constructed with
existing subframes.

[0181] At this time, a maximum of 6 PRS subframes in a time axis may have
the same pattern as that of the generated one subframe (time non-varying
which means there is no change in a time axis), or may have a different
pattern from that of the generated one subframe (time-varying which means
there is a change in a time axis). That is, PRS subframes may be changed
for each subframe number or may not be changed.

[0182] Further, a time of arrival for signal power may be measured in an
OTDOA method by simultaneously considering repetitive patterns
synthetically in order to obtain a time accumulation effect, and each
time of arrival for signal power may be measured for each PRS subframe in
order to discriminate more system-specific information.

[0183] For example, when 2 subframes are periodically used for the PRS
subframe, if a time of arrival for signal power is measured in an OTDOA
method by simultaneously considering all signals (in all particular time
and frequency bands where REs corresponding to the pattern are located)
corresponding to 2 subframe time/frequency patterns synthetically, a time
accumulation effect is obtained so that errors generated in detecting a
UE location may be reduced (performance may be improved). If a time of
arrival for signal power in each PRS subframe is separately measured,
square times of information may be distinct in comparison with a case
where a single subframe is used.

[0184] In a time non-varying case, the existing PRS subframe pattern
generated for each case may be constructed without any change in the
Nsubframe number of subframes to be periodically used in a time axis
in the same pattern. That is represented as table 2 below according to
each case. At this time, a time of arrival for signal power is measured
by simultaneously considering the repetitive Nsubframe number of
subframe patterns synthetically so that a time accumulation effect for
the Nsubframe number of subframes may be obtained.

[0187] In a time varying case, the existing PRS subframe pattern generated
for each case may be constructed in the Nsubframe number of
subframes to be periodically used in a time axis in different patterns
for each subframe. In case 2 where 24 patterns exist, 24 patterns are
cyclic-shifted in a frequency axis by 12 and are not cyclic-shifted or
are cyclic-shifted by 1 in a time axis.

[0188] That is, in a first PRS subframe of case 2, 24 patterns are
generated by a 12 cyclic-shifts in a frequency axis when a cyclic-shift
in a time axis is 0 and 12 cyclic-shifts in a frequency axis when a
cyclic-shift in a time axis is 1 (or 6). Accordingly, 10 cyclic-shifts in
a time axis corresponding to cases where cyclic-shifts are 2-11 (or 1-5
and 7-11) are not used for forming the PRS patterns but may be used for
the rest subframes.

[0189] For example, 24 patterns are generated by 12 cyclic-shifts in a
frequency axis when cyclic-shifts in a time axis are 0 and 1 in a first
PRS subframe, and 24 different patterns from the PRS patterns used in the
first subframe may be generated by 12 cyclic-shifts in a frequency axis
when cyclic-shifts in a time axis are 2 and 3 in a second PRS subframe.
In a third PRS subframe, PRS patterns are generated when cyclic-shifts in
a time axis are 4 and 5, and then the generated PRS patterns are used. In
a fourth RPS subframe, PRS patterns are generated when cyclic-shifts in a
time axis are 6 and 7, and then the generated PRS patterns are used. In a
fifth RPS subframe, PRS patterns are generated when cyclic-shifts in a
time axis are 8 and 9, and then the generated PRS patterns are used. In a
sixth RPS subframe, PRS patterns are generated when cyclic-shifts in a
time axis are 10 and 11, and then the generated PRS patterns are used.

[0190] Through another method, 24 patterns are generated by 12
cyclic-shifts in a frequency axis when cyclic-shifts in a time axis are 0
and 6 in a first PRS subframe in a first PRS subframe, and 24 different
patterns from the PRS patterns used in the first subframe may be
generated by 12 cyclic-shifts in a frequency axis when cyclic-shifts in a
time axis are 1 and 7 in a second PRS subframe. In a third PRS subframe,
PRS patterns are generated when cyclic-shifts in a time axis are 2 and 8,
and then the generated PRS patterns are used. In a fourth RPS subframe,
PRS patterns are generated when cyclic-shifts in a time axis are 3 and 9,
and then the generated PRS patterns are used. In a fifth RPS subframe,
PRS patterns are generated when cyclic-shifts in a time axis are 4 and
10, and then the generated PRS patterns are used. In a sixth RPS
subframe, PRS patterns are generated when cyclic-shifts in a time axis
are 5 and 11, and then the generated PRS patterns are used.

[0198] When M=12, T=24 and 24 distinct 12×12 modular sonar sequences
are generated. When Nsubframe=6, in a first PRS subframe, 24
patterns are generated by 12 cyclic-shifts in a frequency axis when a
cyclic-shift in a time axis is 0 and 12 cyclic-shifts in a frequency axis
when a cyclic-shift in a time axis is 6. In a second PRS subframe, 24
different patterns from the PRS patterns used in the first subframe may
be formed, and the different patterns are generated by 12 cyclic-shifts
in a frequency axis when cyclic-shifts are 1 and 7 in a time axis. In a
third RPS subframe, 24 different PRS patterns are generated by 12
cyclic-shifts in a frequency axis when cyclic-shifts in a time axis are 2
and 8. In a fourth RPS subframe, 24 different PRS patterns are generated
by 12 cyclic-shifts in a frequency axis when cyclic-shifts in a time axis
are 3 and 9. In a fifth RPS subframe, 24 different PRS patterns are
generated by 12 cyclic-shifts in a frequency axis when cyclic-shifts in a
time axis are 4 and 10. In a sixth RPS subframe, 24 different PRS
patterns are generated by 12 cyclic-shifts in a frequency axis when
cyclic-shifts in a time axis are 5 and 11.

[0199] In equation 6, .left brkt-bot.t/M.right brkt-bot. is a quotient of
t/M and used for a cyclic-shift in a time axis. (t mod M) is a remainder
of t/M and used for a cyclic-shift in a frequency axis.

[0200] c) A truncated M×(N-N') modular sonar sequence
fnsubframe.sub.,t'(i), 0≦i<N-N' is generated by
equation 12 below. Of course, there may be a case where the truncation is
not required, that is, N' has a value of "0".

fnsubframe.sub.,t'(i)=fnsubframe.sub.,t(i) for
0≦i<N-N' (12)

[0201] d) The PRS pattern is generated. In the PRS pattern in a
two-dimensional structure including M×(N-N') frequency
(subcarrier)/time (symbol), a PRS pattern for an OTDOA positioning
subframe is formed in all positions where an ith available symbol axis
and a fnsubframe.sub.,t'(i)th available subcarrier axis
intersect for 0≦i<N-N' (0=N-N+ mod (N-N')).

[0202] e) The PRS sequence is mapped to the PRS pattern of the generated
OTDOA positioning subframe.

[0203] In a first PRS subframe of case 3, 12 patterns are generated by 12
cyclic-shifts in a frequency axis when a cyclic-shirt in a time axis is
0. Accordingly, the remaining 11 cyclic-shifts in a time axis
corresponding to cases where cyclic-shifts are 1-11 in a time axis are
not used for forming the PRS signals but may be used for the remaining
subframes.

[0211] When M=12, T=24 and 12 distinct 12×12 modular sonar sequences
are generated. When Nsubframe=6, in a first PRS subframe, 12
patterns are generated by 12 cyclic-shifts in a frequency axis when a
cyclic-shift in a time axis is 0. In a second PRS subframe, 12 different
patterns from the PRS patterns used in the first subframe may be formed,
and the different patterns are generated by 12 cyclic-shifts in a
frequency axis when a cyclic-shift is 2 in a time axis. In third, fourth,
fifth, and sixth RPS subframes, 12 different PRS patterns are generated
by 12 cyclic-shifts in a frequency axis when cyclic-shifts in a time axis
are 4, 6, 8, and 10, respectively.

[0212] In equation 13, (t mod M) is a remainder of t/M and used for a
cyclic-shift in a frequency axis.

[0213] c) A truncated M×(N-N) modular sonar sequence
fnsubframe.sub.,t'(i), 0≦i<N-N' is generated by
equation 14 below. Of course, there may be a case where the truncation is
not required, that is, N' has a value of "0".

fnsubframe.sub.,t'(i)=fnsubframe.sub.,t(i) for
0≦i<N-N' (14)

[0214] d) The PRS pattern is generated. In the PRS pattern in a
two-dimensional structure including M×(N-N') frequency
(subcarrier)/time (symbol), a PRS pattern for an OTDOA positioning
subframe is formed in all positions where an ith available symbol axis
and a fnsubframe.sub.,t'(i)th available subcarrier axis
intersect for 0≦i<N-N' (0=N-N' mod (N-N')).

[0215] e) The PRS sequence is mapped to the PRS pattern of the generated
OTDOA positioning subframe.

[0216] Similarly, in a first PRS subframe of case 4, 6 patterns are
generated by 6 cyclic-shifts in a frequency axis when a cyclic-shift in a
time axis is 0. Accordingly, the remaining 11 cyclic-shifts in a time
axis corresponding to cases where cyclic-shifts are 1-11 in a time axis
are not used for forming the PRS signals but may be used for the
remaining subframes. For example, in a second PRS subframe, 12 different
patterns from the PRS patterns used in the first subframe may be formed,
and the different patterns are generated by 12 cyclic-shifts in a
frequency axis when a cyclic-shift is 2 in a time axis.

[0217] In a third PRS subframe, different PRS patterns are generated when
a cyclic-shift in a time axis is 4, and then the generated PRS patterns
are used. In a fourth RPS subframe, different PRS patterns are generated
when a cyclic-shift in a time axis is 6, and then the generated PRS
patterns are used. In a fifth RPS subframe, different PRS patterns are
generated when a cyclic-shift in a time axis is 8, and then the generated
PRS patterns are used. In a sixth RPS subframe, different PRS patterns
are generated when a cyclic-shift in a time axis is 10, and then the
generated PRS patterns are used.

[0225] When M=12, T=24 and 12 distinct 12×12 modular sonar sequences
are generated. When Nsubframe=6, in a first PRS subframe, 6 patterns
are generated by 6 cyclic-shifts in a frequency axis when a cyclic-shift
in a time axis is 0. In a second PRS subframe, 12 different patterns from
the PRS patterns used in the first subframe may be formed, and the
different patterns are generated by 12 cyclic-shifts in a frequency axis
when a cyclic-shift is 2 in a time axis.

[0226] In a third PRS subframe, different PRS patterns are generated when
a cyclic-shift in a time axis is 4, and then the generated PRS patterns
are used. In a fourth RPS subframe, different PRS patterns are generated
when a cyclic-shift in a time axis is 6, and then the generated PRS
patterns are used. In a fifth RPS subframe, different PRS patterns are
generated when a cyclic-shift in a time axis is 8, and then the generated
PRS patterns are used. In a sixth RPS subframe, different PRS patterns
are generated when a cyclic-shift in a time axis is 10, and then the
generated PRS patterns are used.

[0227] In equation 15, (t mod M) is a remainder of t/M and used for a
cyclic-shift in a frequency axis.

[0228] c) A truncated M×(N-N) modular sonar sequence
fnsubframe.sub.,t'(i), 0≦i<N-N' is generated by
equation 16 below. Of course, there may be a case where the truncation is
not required, that is, N' has a value of "0".

fnsubframe.sub.,t'(i)=fnsubframe.sub.,t(i) for
0≦i<N-N' (16)

[0229] d) The PRS pattern is generated. In the PRS pattern in a
two-dimensional lo structure including M×(N-N') frequency
(subcarrier)/time (symbol), a PRS pattern for an OTDOA positioning
subframe is formed in a position where an ith available symbol axis and a
fnsubframe.sub.,t(i)th available subcarrier axis intersect and
a point where an ith available symbol axis and a
(fnsubframe.sub.,t(i)+.left brkt-bot.M/2.right brkt-bot.) mod
Mth available subcarrier axis intersect for 0≦i<N-N' (0=N-N'
mod (N-N')).

[0230] e) The PRS sequence is mapped to the PRS pattern of the generated
OTDOA positioning subframe.

[0231] At this time, a time of arrival for signal power is measured by
simultaneously considering the repetitive N number of subframe patterns
synthetically so that a time accumulation effect for the N number of
subframes may be obtained.

[0241] In table 5, f0.sup.(i) of case 4.sup.(n--subframe)
corresponds to cyclic-shifting f0.sup.(i) Case 4.sup.(0) in a time
axis by 2*(n_subframe), and t=NIDcell mod 6.

[0242] As described in the above method, the time of arrival for signal
power is measured in an OTDOA method by simultaneously considering
repetitive patterns synthetically in order to obtain a time accumulation
effect. That is, when two or more subframes are periodically used for the
PRS subframe, if a time of arrival for signal power is measured in an
OTDOA method by simultaneously considering all signals (in all particular
time and frequency bands where REs corresponding to the pattern are
located) corresponding to two or more subframe time/frequency patterns
synthetically, a time accumulation effect is obtained so that errors
generated in detecting a UE location may be reduced (performance may be
improved).

[0243] Unlike the above case, the time of arrival for signal power in each
PRS subframe is measured in order to discriminate more system-specific
information. That is, if a time of arrival for signal power in each PRS
subframe is separately measured, more pattern types may be generated in
comparison with a case where a single subframe is used and thus more
system-specific information may be discriminated.

[0244] For example, when 2 subframes are used, a total of 24 patterns are
generated in a first subframe through case 2 and accordingly a maximum of
24 system-specific information pieces (cell-IDs) may be discriminated.
Similarly, 24 patterns may be generated in a second subframe. When each
time of arrival for signal power in each PRS subframe is separately
measured, a total of 24*24=576 patterns may be obtained through 24
patterns included in each of 2 subframes. Accordingly, when 2 subframes
are constructed, 576 system-specific information pieces (cell-IDs) may be
discriminated.

[0245] When 4 subframes are used, 24*24*24*24 system-specific information
pieces may be discriminated in the same manner. When the system-specific
information is a cell-ID, since current LTE Rel-8 PCIs (Physical Cell
Identities) having the total number of 504 may be discriminated by the
number of cases of 576 patterns. When 4 subframes are divided into 2
groups each having 2 subframes and the above method is applied to each
group, 24*24=576 system-specific information pieces may be discriminated
and simultaneously a time accumulation effect as much as 2 may be
obtained.

[0246] When 6 subframes are used, 24*24=576 system-specific information
pieces may be discriminated and simultaneously a time accumulation effect
as much as 3 may be obtained by applying the same method to each group,
the 6 subframes being divided into 3 groups and the 3 groups each having
2 subframes.

[0251] In table 6, ) f0.sup.(i) of case 2.sup.(1) corresponds to
cyclic-shifting f0.sup.(i) of case 2.sup.(0) in a time axis by 2 (or
1), and t of case 2.sup.(0) is still defined by t=NIDcell mod
24, but t of case 2.sup.(1) is defined by t=.left
brkt-bot.NIDcell/24.right brkt-bot..

[0252] That is, when times of arrival for signal power are separately
measured in each of the first PRS subframe and the second PRS subframe
having generated 24 different patterns, a total of 24*24=576 patterns may
be obtained through 24 patterns included in each of 2 subframes.
Accordingly, 576 system-specific information pieces (cell-IDs) may be
discriminated.

[0254] In table 7, f0(i) of case 2.sup.(1) corresponds to
cyclic-shifting f0(i) of case 2.sup.(0) in a time axis by 2 (or 1),
f0(i) of case 2.sup.(2) corresponds to cyclic-shifting f0(i) of
case 2.sup.(0) in a time axis by 4 (or 2), f0(i) of case 2.sup.(3)
corresponds to cyclic-shifting f0(i) of case 2.sup.(0) in a time
axis by 6 (or 3), and t of case 2.sup.(0) and case 2.sup.(2) is still
defined by t=NIDcell mod 24, but t of case 2.sup.(1) and case
2.sup.(3) are defined by t=.left brkt-bot.NIDcell/24.right
brkt-bot..

[0255] When 4 subframes are used, 24*24=576 system-specific information
pieces may be discriminated and simultaneously a time accumulation effect
as much as 2 may be obtained by applying the same method to each group,
the 4 subframes divided into 2 groups and the 2 groups each having 2
subframes.

[0257] In table 8, f0(i) of case 2.sup.(n--subframe)
corresponds to cyclic-shifting f0(i) of case 2.sup.(0) in a time
axis by 2*(n_subframe) or n_subframe, and t of case
2.sup.(n--subframe=even number (0, 2, 4)) is still defined by
t=NIDcell mode 24, but t of case
2.sup.(n--subframe=odd number (1, 3, 5) defined by t=.left
brkt-bot.NIDcell/24.right brkt-bot..

[0258] When 6 subframes are used, 24*24=576 system-specific information
pieces may be discriminated and simultaneously a time accumulation effect
as much as 3 may be obtained by applying the same method to each group,
the 6 subframes being divided into 3 groups and the 3 groups each having
2 subframes.

[0259] Hereinafter, an example of a downlink physical channel in a
wireless communication system to which a method and an apparatus for
allocating PRS patterns by using the M×N modular sonar sequence
according to an embodiment of the present invention is described.

[0260] FIG. 17 illustrates a structure of the downlink physical channel in
a wireless communication system to which embodiments of the present
invention are applied.

[0261] Referring to FIG. 17, the wireless communication system 900 to
which embodiments of the present invention are applied includes a
scrambler 910, a modulation mapper 912, a layer mapper 914, a precoder
916, a resource element mapper 918, and an OFDM signal generator 920.
Further, the wireless communication system 900 includes a PRS mapper 922.
At this time, the PRS mapper may be the same as the aforementioned PRS
mapper 120 or 630 illustrated in FIG. 1 or 9. The PRS mapper 922 is
associated with the resource element mapper 918 and performs a mapping
process in a resource element corresponding to a PRS resource in a signal
resource mapping process in all resource elements of the resource mapper
918. That is, the PRS mapper corresponds to a device for performing a
special function of the resource element mapper 918 associated with the
PRS in the mapping of the resource element. When both components are the
same, the wireless communication system 900 may include other components
other than the PRS mappers 120 and 630 of FIGS. 1 and 9.

[0262] Meanwhile, the wireless communication system 900 may be a
communication system of a base station or a transmission device of a base
station including an apparatus illustrated in FIG. 1 or FIG. 9 for
transmitting the PRS, respectively.

[0263] Bits input in a form of codewords via a downlink channel coding are
scrambled by the scrambler 910 and then input to the modulation mapper
912. The modulation mapper 912 modulates the scrambled bits to complex
modulation symbols, and the layer mapper 914 maps the complex modulation
symbols to one transmission layer or a plurality of transmission layers.
Then, the precoder 916 precodes complex modulation symbols on each
transmission channel of an antenna port. Next, the resource element
mapper 918 maps the complex modulation symbol for each antenna port to a
corresponding resource element. Meanwhile, the PRS mapper 922 forms a PRS
pattern from a second M×N modular sonar sequence generated through
the M×N modular sonar sequence generator 110 described above with
reference to FIG. 1 and maps the PRS, or forms a PRS pattern from a
second N×(N-N') modular sonar sequence generated through the
N×(N-N') modular sonar sequence generator 110 described above with
reference to FIG. 1 and maps the PRS.

[0264] The PRS mapper 922 is generated by a particular RPS sequence in the
wireless communication system 900, allocates PRSs generated via at least
one of apparatuses 910, 912, 914, and 916 to resource elements
corresponding to resources, in which a particular OFDM symbol (time axis)
and a subcarrier (frequency axis) are located, according to PRS patterns
formed from the modular sonar sequence, and multiplex with a base station
transmission frame according to a predetermined frame timing.

[0265] At this time, the existing RS and control signals and data input
from the precoder 916 are allocated to resource elements corresponding to
resources, in which a particular OFDM symbol (time axis) and a subcarrier
(frequency axis) are located, by the resource element mapper 918. Here,
the PRS mapper corresponds to an apparatus responsible for performing a
special function (of forming a PRS pattern to map the PRS) added to the
resource element mapper 918 in order to allocate the PRS to a
corresponding each resource element.

[0266] Then, the OFDM signal generator 920 generates a complex time domain
OFDM signal for each antenna. The complex time domain OFDM signal is
transmitted through an antenna port.

[0267] The structure of generating the downlink physical channel signal in
the wireless communication system to which embodiments of the present
invention are applied has been described with reference to FIG. 17, but
the present invention is not limited thereto. That is, in the structure
of generating the downlink physical channel signal in the wireless
communication system to which embodiments of the present invention is
applied, other components may be omitted, replaced with or changed to
other components, or other components may be added.

[0268] FIG. 18 illustrates a structure of a receiver in a wireless
communication system.

[0269] Referring to FIG. 18, a receiver 1000 of a terminal in a wireless
communication system includes a reception processor 1010, a decoder 1912,
and a controller 1014. At this time, the receiver 1000 may be a base
station receiving information on the received PRS again from a terminal
(UE) including the apparatus of FIG. 1 or FIG. 9 for receiving and
decoding the PRS.

[0270] The signal received through each antenna port is converted to a
complex time domain signal by the reception processor 1010. Further, the
reception processor 1010 extracts PRSs of particular resource elements
from received signals. The decoder 1012 decodes the extracted PRSs. The
controller 1014 measures a distance from a base station by using a
relative arrival time from the base station through information on the
decoded PRSs.

[0271] At this time, the controller 1014 can calculate the distance from
the base station by using the relative arrival time from the base
station, or the controller 1014 transmits the relative arrival time to
the base station and then the base station can calculate the distance. At
this time, since distances from three or more base stations are measured,
a terminal location may be calculated.

[0272] At this time, when PRS patterns specific for each cell are
generated and transmitted by using the modular sonar sequence in two or
more subframes, the receiver accumulates information received from PRS
patterns of subframes for a predetermined time and then can measure a
relative arrival time from each cell.

[0273] As described above, the time of arrival for signal power may be
measured in an OTDOA method by simultaneously considering repetitive
patterns synthetically in order to obtain the time accumulation effect.
That is, when two or more subframes are periodically used for the PRS
subframe, if a time of arrival for signal power is measured in an OTDOA
method by simultaneously considering all signals (in all particular time
and frequency bands where REs corresponding to the pattern are located)
corresponding to two or more subframe time/frequency patterns
synthetically, a time accumulation effect is obtained so that errors
generated in detecting a UE location may be reduced (performance may be
improved).

[0274] Unlike the above case, each time of arrival for signal power in
each PRS subframe may be measured in order to discriminate more
system-specific information. That is, if a time of arrival for signal
power in each PRS subframe is separately measured, more pattern types may
be generated in comparison with a case where a single subframe is used
and thus more system-specific information may be discriminated.

[0275] The receiver 1000 is a device, which makes a pair with the wireless
communication system or transmitter 900 described with reference to FIG.
17 and receives a signal transmitted from the transmitter 900. The
receiver 1000 includes components for processing a signal of a reverse
process of the transmitter 900. Accordingly, a detailed description for
the receiver 1000 may be replaced with a detailed description for the
components for processing the signal of the reverse process of the
transmitter 900 in a one-to-one correspondence manner.

[0276] So far, embodiments of the present invention have been described
with reference to the figures, but the present invention is not limited
thereto.

[0277] Meanwhile, the methods of generating 144, 24, 12, and 6 PRS
patterns in one subframe are described in the embodiments of the present
invention, but they are only illustrative. Further, various numbers of
PRS patterns may be generated according to one subframe type and the PRS
patterns may be used for the positioning of the OTDOA method.

[0278] In the embodiments, the method of generating the PRS patterns with
different patterns, which are specific for each cell, by using the
modular sonar sequence based on one subframe has been described. However,
in one or more subframes of a radio frame including subframes, the PRS
patterns specific for each cell may be generated by using the
aforementioned modular sonar sequence. For example, in one radio frame
including 10 subframes, PRS patterns specific for each cell may be
generated in 1, 2, 3, 4, or 6 subframes by using the modular sonar
sequence.

[0279] Further, the PRS patterns specific for each cell may generated by
using the modular sonar sequence in the particular number of subframes in
every radio frame on a frame period of 16, 32, 64, or 128 in an aspect of
each radio frame. For example, when the 10 number of 1 ms subframes
consist of one radio frame (a total of 10 ms), cell-specific PRS patterns
may be generated in 1, 2, 3, 4, or 6 subframes of one radio frame by
using the modular sonar sequence on a 32 radio frame period (320 ms).

[0280] At this time, when cell-specific PRS patterns are generated and
transmitted by using the modular sonar sequence in two or more subframes,
the receiver accumulates information received from PRS patterns of
subframes for a predetermined time and then can measure a relative
arrival time from each cell.

[0281] In the embodiments, it has been described that the M×N
modular sonar sequence is used for generating the PRS patterns, but the
M×N modular sonar sequence according to the present invention may
be used for other reference signals other than the PRS, for example, a
particular signal inserted into a frequency domain grid for a frequency
domain channel estimation at regular or irregular intervals, a reference
signal which is a symbol, a reference symbol, or a pilot symbol. For
example, reference signals in an uplink transmission include a DM-RS
(DeModulation RS) and an SRS (Sounding RS). In a downlink transmission,
the M×N modular sonar sequence may be used in a permissible range
for generating patterns of a CRS (Cell-specific RS), an MBSFN RS, and a
UE-specific RS as the reference signal, and a CSI-RS (CQI-RS) as the
reference signal transmitted from a base station in order to enable a
user device (terminal) to obtain Channel Spatial Information (CSI) of a
central cell or neighbor cells. Of course, the M×N modular sonar
sequence may be used for all reference signals currently defined or to be
defined in the future, or all reference signals having a changed
definition.

[0282] In the embodiments, it has been described that the M×N
modular sonar sequence may be used for forming the pattern of the
reference signals including the PRS, but one or more sequences having the
same characteristic as that of the aforementioned M×N modular sonar
sequence may be used for generating the pattern of the reference signal
including the PRS in the present invention. For example, as described in
the example, the M×N modular sonar sequence where M=N has the same
characteristic as that of the N×N modular (or perfect) costas
array. In this case, the modular sonar sequence includes the modular
costas array.

[0283] A method of generating the PRS according to still another
embodiment of the present invention is described below.

[0284] 1. A basic PRS pattern is formed in a 1/2 resource block including
2 slots and 6 subcarriers by a particular sequence. At this time, an
example of a used particular sequence is {0, 1, 2, 3, 4, 5, 6}. Further,
the 2 slots correspond to 2 time slots included in subframes for the
positioning. Here, the method of forming the PRS patterns by the
particular sequence is described below.

[0285] 1-a) When the particular sequence corresponds to
f(i)={f(0),f(1),f(2),f(3),f(4),f(5)}={0, 1, 2, 3, 4, 5, 6}, the PRS
pattern is formed in a position of a subcarrier on a frequency domain
corresponding to a first value of sequences in the last symbol in each of
the two slots as shown in FIG. 19. That is, in the last symbol, the PRS
pattern is formed in a 0th subcarrier position since a first value
of sequences is 0. Next, in a second symbol from the last, the PRS
pattern is formed in a subcarrier position on a frequency domain
corresponding to a second value of sequences. That is, in the second
symbol from the last, the PRS pattern is formed in 1st subcarrier
position since the second value of sequences is 1. In the same way, PRS
patterns are formed in corresponding subcarrier positions on a frequency
domain corresponding to values of sequences from the last symbol to a
6th symbol from the last in each of the two slots.

[0286] 1-b) As shown in FIG. 20, PRS patterns formed in positions
corresponding to symbol axes including control regions such as a PDCCH
(Physical Downlink control CHannel), a PHICH (Physical Hybrid-ARQ
Indicator CHannel), and a PCFICH (Physical Control Format Indicator
CHannel) and a CRS (Cell-specific Reference Signal), and REs (Reference
Elements) including a PSS (Primary Synchronization Signal), an SSS
(Secondary Synchronization Signal), and a BCH (Broadcast Channel) are
excluded from the generated basic PRS patterns.

[0287] 1-equation) A process of forming the basic PRS patterns through
1-a) and 1-b) is represented by an equation below.

[0288] When it is determined that v indicates a value for defining
locations of different PRSs in a frequency domain, NsymbDL
indicates the number of all OFDM symbols in each slot in a downlink, the
basic PRS pattern for a corresponding Ith OFDM symbol at each slot
is formed based on equation 17 below.

[0289] A value of NsymbDL is 7 when a normal CP is used, a value
of NsymbDL is 6 when an extended CP is used. A value of
(ns mod 2) is 0 in even slots, and a value of (ns mod 2) is 1
in odd slots. Accordingly, in equation 17 may be defined as follows.

[0290] 2. The basic PRS patterns formed in 2 slots consisting of one
subframe and 1/2 resource block including 6 subcarriers are allocated to
the Nsubframe number of subframes up to a system bandwidth in a
frequency axis and every particular period in a time axis.

[0291] For example, when a system bandwidth corresponds to 10 Mhz in a
frequency axis, a total of 50 RBs exist, so that the basic PRS pattern
formed in the 1/2 RB is repeated 100 times in a frequency axis without
any change. When the number of total RBs corresponding to the downlink
system bandwidth is NRBDL, the total number of 2NRBDL
is repeated.

[0292] The basic PRS patterns are allocated in the Nsubframe number
of subframes in every particular period, and are differently distributed
for each Subframe Number (SFN), each cell-specific information piece such
as a PCI (Physical Cell Identity), and each time axis, unlike in a
frequency axis. That is implemented by identically cyclic-shifting
subcarrier locations, in which the PRS in each symbol is formed, as much
as vshift, by adding vshift indicating values to be shifted in
a frequency axis to indicating values for defining locations of different
positioning reference signals in a frequency domain according to a
subframe number and cell-specific information.

[0293] Process 2 for a kth subcarrier in an entire system bandwidth
including NRBDLNscRB number of subcarriers is
represented as equation 12. NRBDL refers to the number of total
RBs corresponding to the downlink system bandwidth, NscRB
refers to the number of subcarriers in one RB, and a normal subframe
including the positioning subframe may use equation 18 below.

k=6m+(v+vshift) mod 6 m=0,1, . . . , 2NRBDL- (18)

[0294] In equation 18, v indicates values for defining locations of
different PRSs described in process 1 in a frequency domain, and
vshift indicates values for identically and additionally
cyclic-shifting subcarrier locations, in which the PRS in each symbol is
formed, according to a subframe number and cell-specific information. At
this time, vshift may include remainders generated by dividing a
value generated by the subframe number and a cell-specific information
function by 6, which is a maximum available frequency shift value.
Particularly, is obtained by deriving one or more pseudo-random sequence
values from a pseudo-random sequence, which is generated with
cell-specific information as an initial value such as a PCI, by a
function of positioning subframe numbers, multiplying the derived
pseudo-random sequence values by a predetermined constant, calculating a
sum of the multiplied values, and then obtaining a remainder remaining
after dividing the sum by 6, which corresponds to a maximum available
frequency shift value. The above function is represented as equation 19
below.

[0295] In equation 19, 0≦NCellID<504 denotes a PCI, a
denotes a constant, c(i) denotes a pseudo-random sequence, and
cinit=NCellID is given to an initial value of c and
initialized in every subframe for each positioning.

[0296] Processes 1 and 2 together are represented as an equation below.

[0297] That is, a PRS rl,ns(m) mapped to ak,l.sup.(p),
which is a complex-valued modulation symbol used as a positioning
reference symbol for an antenna port p in a ns th slot is
represented as equation 20.

[0299] At this time, v indicating values for defining locations of
different positioning reference signals in a frequency domain and
vshift are represented as equation 21 below. Particularly,
vshift is a cell-specific and positioning subframe number-specific
value.

[0300] In equation 21, nsubframe corresponds to a positioning
subframe number, and cinit-NCellID is given as an initial
value of c in pseudo-random sequence c(i) and is initialized in every
subframe for each positioning.

[0301] Methods of generated PRS patterns by using the modular sonar
sequence proposed herein may be applied to all OFDM-based wireless mobile
communication systems. Examples of OFDM-based wireless mobile
communication systems include an E-UTRAN (LTE), an E-EUTRAN
(LTE-Advanced), WIBRO, and Mobile Wi-MAX, and may be also applied to all
wireless mobile communication systems in which all OFDM-based mobile
communication terminals require the positioning.

[0302] While the exemplary embodiments have been shown and described, it
will be understood by those skilled in the art that various changes in
form and details may be made thereto without departing from the spirit
and scope of this disclosure as defined by the appended claims and their
equivalents. Thus, as long as modifications fall within the scope of the
appended claims and their equivalents, they should not be misconstrued as
a departure from the scope of the invention itself.

[0303] This application is further related to the U.S. Patent Application
having attorney docket number (your docket number), which claims priority
from and the benefit of Korean Patent Application Nos. 10-2009-0031548,
10-2009-0038564, 10-2009-0056705, 10-2009-0056708, and 10-2009-0059978,
filed on Apr. 10, 2009, Apr. 30, 2009, Jun. 24, 2009, Jun. 24, 2009, and
Jul. 1, 2009, respectively. These applications, assigned to the assignee
of the current application, are hereby incorporated by reference for all
purposes as if fully set forth herein.

Patent applications by Kibum Kwon, Ansan-Si KR

Patent applications by Kitae Kim, Suwon-Si KR

Patent applications by Sungjin Suh, Seoul KR

Patent applications by Sungjun Yoon, Seoul KR

Patent applications by PANTECH CO., LTD.

Patent applications in class Particular set of orthogonal functions

Patent applications in all subclasses Particular set of orthogonal functions